When compressed moving images are provided over broadcasting, network services, and the like, the upper limit of a frame frequency that can be played back is restricted by a decoding capability of a receiver. Therefore, a service side is required to take the playback performance of prevalent receivers into account, and restrict the service to a low frame frequency only or simultaneously provide multiple high and low frame frequency services.
A support for high frame frequency services increases the cost of the receiver, which becomes a barrier to rapid diffusion of the service. If only low-cost receivers dedicated to low frame frequency services are widespread in early times, and the service side starts a high frame frequency service in the future, the new service is completely unwatchable without a new receiver, which becomes a barrier to diffusion of the service.
For example, a time direction scalability is proposed, in which image data of each picture constituting moving image data is subjected to hierarchical encoding in HEVC (High Efficiency Video Coding) (see Non-patent Document 1). A reception side can identify a hierarchy of each picture on the basis of a temporal ID (temporal_id) inserted into the header of a NAL (Network Abstraction Layer) unit and perform selective decoding to a hierarchy corresponding to a decoding capability.
[Non-patent Document 1] Gary J. Sullivan, Jens-Rainer Ohm, Woo-Jin Han, Thomas Wiegand, “Overview of the High Efficiency Video Coding (HEVC) Standard” IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECNOROGY, VOL. 22, NO. 12, pp. 1649-1668, DECEMBER 2012